But apparently "final yield" can be affected my many other factors...
Of course it can and the information you provided is accurate. But we weren’t anywhere near the point of talking about other sources of yield loss when I was trying to convey that wafer yield and final yield measure very different parameters.
Seems like it wouldn't be too difficult to ask Lebby or someone at LWLG what exactly he means when he refers to yield. That would put an end to the speculation anyhow.